Nitrates WALT state why nitrates are important and

Nitrates • WALT: state why nitrates are important and be able to analyse some data on minerals in plants

Last lesson, we learnt…. . • In order to survive, plants need ………… • Plants are called producers because they …………………. through …………… Today, we will look at one mineral in particular; nitrates.

Nitrates • Nitrates are needed to make proteins • Just like in animals, proteins are needed by plants for………………. . – Growth and repair • Nitrates are obtained from the soil and absorbed through the roots in the water • If the soil does not contain enough nitrates, farmers can use fertiliser (chemicals containing nitrates which are sprayed onto the soil)

The use of fertilisers can be a big problem if large amounts of nitrates run into rivers and streams. Can you think why? • Algae in the water overgrows and makes the water green. • This blocks the light for other plants in the water which die • Fish and larger pond animals die • Drinking water becomes polluted

This is a huge problem in Lake Naivasha

We are going to test the effect of different levels of nitrate on the growth of some cress seeds • How will we do this? • How will we keep it a fair test?

When you have set up your cress seeds • Put a sub-heading in your books “KS 3 Science: Life Processes” “P. 42, 43 and 44” • Answer the questions from the books in full sentences